Aromatic monoaroyl diamines



Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE WILHELM NEELMEIER, OFLEVERKUSEN-ON-THE-IRHINE, AN D WILHELM LAMBER-Z, OF

WIESDORF, GERMANY, ASSIGNORS TO ANILINE WORKS, INC, OF NEW YORK, N. Y.,A. CORPORATION OF DELAWAR B nnomerrc uonoanom nrnmrnns No Drawing.Application med .Janlary.5, 19 31, Serial No. 506,834, and in'GermanyJanuary 15, 1930,

The present invention relates to a process of preparingmonoaroylrdiamines of the henzene and naphthalene series, moreparticular.-

7 1y it relates to compounds which may e represented by the probablegeneral formu a;

- NH-ooR' w wherein R and R stand for a benzene-or naphthalene nucleusand wherein B may be substituted by alkyl, alkoxy or halogen, and Rmaybe substituted by alkyl, alkoxy, halogen or the nitro group.

The manufacture of monoaroyl phenylenediamines by reduction or aroylatednitroani. lines is known. In consequence of the sparing solubility ofthe aroylated nitroan line and of the reduction products in water and inthe customary organic solvents, such as alcohol, benzene and the like,the process presents technical difiiculties in many cases.

In accordance vwith the present invention A monoaroyl-diamines of {thebenzene and naph thalene seriesoi the above identified general formulaare produced in a smooth reaction by starting with a nitroamine of thebenzene or naphthalene series, sulfonating the same in the amino groupin the usual mannor by treating with chloro-sulfonic acid in an inertorganic solvent in presence of a tertiary base, favorably in a tertiarybase 3 which acts at the same as solvent and acid-binding agent, such aspyridine or dimethyl-o-toluidine, then reducingthe nitm group of thearomatic sulfamic acid :formed i the usual manner by treating the (samein I aqueous solution with iron and acetic acid or formic acid. Thearomatic amino-.snlfamic acid thus produced is then .aiuoy-lated intheamino group by treating with a benzoyle or naphthoyl-hal-ogenide, whichmay be substituted in the nuclei by halogen, alkoxy or the nitro group,in an alkaline reacting aqueous solution, and finally the sulfamic acidgroup is split up in the usual manner .by heating with dilute mineralacid.

i The whole process may be illustrated by the following scheme:

Over the processes heretofore used for the manufacture of monoaroylateddiamine compounds of the benzene or naphthalene series, the presentprocess has the advantage that apart from the first step the process canbe carried out in aqueous solution due to the presence of the sulfamicacid group, and that iron which is the cheapest reducing agent can beused. The process also renders possihis in many cases the manufacture ofbases which in consequence of the difliculty of obtaining the nitroaminecompounds could only 70 be produced other methods in a tedious orcumbersome manner. Thus the compounds of the formulae:

mr-co-oun NH:

.65! 02H; which in accordance with this invention are obtainable fromthe compounds of the formulae.

l i N0: N112 Hm or om respectively "CH: 002E;

were only to be obtained from the nitro- 99 amines of the formulae:

these nitroamines :bejing obtainableonly with difiiculty. 109

The following examples will illustrate our invention, withoutrestricting it thereto:

E wample 1.4-amino-6-benzoylamino-lfl-dimethylbenzene 268 kgs. of thesodium salt of 6-nitro-1.3- dimethylbenzene-4-sulfamic acid (obtained bysulfonating in the amino 4-amino-1.3-dimethylbe1izene with fchlorosulfonic'acid in the presence of a tertiary base) are reduced in theusual manner at 60-70 C. with iron and formic acid. When V the reactionis complete, the mass is rendered alkaline and the amino compoundpresent in the solution is pressed out from the iron oxide slud e. Thenthere are gradually. added to the ltrate at 30 Ci, with good stirring,

145 kgs. of benzoylchloride, and the mixture is kept weakly alkaline bymeans ofsodium carbonate. Then it is heated to 70-80- C., the mixture isrendered weakly acid to Congo by means of hydrochloric acid, and, at thesame time, the temperature is raised to 8(1-90 After a short time thesaponifica- "tion is complete, the hydrochloric acid salt of the benzeneis precipitated, white lustrous needles, by the addition of common saltit is separatednearly quantitatively. Then after filtering by suction,it is again dissolved in hot water and filtered; the

4-amino-6-benzoylamino-1.3-dimethylbase 1s precipitated with sodiumcarbonate.

ing'point 177 C.

White needles, melting point '17 6 C. Cal- ,culated on thenitroarylsulfamic acid employedthe yield is 88%.

On aroylating instead of benzoylchloride for example, with the chlorideof the phenylacetic acid the corresponding phenacetyl compound isobtained. White needles, melt- Eaiample 2.-5-amin0-2-benzoylarninoeicresolmethylether complete, the hydrochloric acid salt -of 5- amino 2benzoylamino 4 cresolmethylether separates, while still hot, in whitelustrous needles, and by dissolving in hot water, filtering andprecipitating with sodium carbonate, the free base is obtained. Whiteneedles, melting oint 185 ()4 Calculated on the ni- I tro-aroy sulfamicacid used the yield is 94%.

,Onemploying instead of benzoylchloride for'example cinnamic acidchloride oro-' chlorophenoxyacetic acid chloride, the corregroup of6-nitro "white needlesof the'melting point 140.59

while still hot, in

sponding cinnamoyl base or the o-chlorophenoxyacetyl compoundrespectively are obtained.

(1) 5 -amino 2-cinn amoylamino-4-cresolmethylether (free base) paleyellowish col-' ored' lorigneedles of'the melting point (2) v5-amino-2-(o-chlorophenoxy) -acetylamino 4-cresol-methylether (free base) Example3.2-amino-5-benzoylaminO-I- methowg d ethomybenzem 314 kgs. of.1-methoxy-4-ethoxy-5-nitrobenzene-Q-sulfamic acid (sodium salt)(obtained bysulfonating in the amino group of1-methoxy-4-ethoxy-2-amino-5-nitrobenzene) are reduced as described in(Example 1), aroylated in aqueous soda solution with 145 kgs. ofbenzoylchloride, and the sulfonic group is saponified with hydrochloricacid. By redissolving the hydrochloric acid salt with hot water andprecipitating with sodium carbonate, the free base is obtained. Whiteneedlesof the melting point 117 C. Calculated on the nitroarylsulfamicacid used the yield is 80%.

Ewample 4. -4 benzoylamino-l mphthylamine 290 kg's. of the sodium saltof 4-nitronaphthalene-l-sulfamic acid (produced by sulfonating in thethylamine) are reduced as described in (Example 1), 'aroylated inaqueous soda solution.

with 145 of benzoylchloride, and the sulfonic group is split off bymeans of hydrochloric, acid. By re-dissolving' the hydrochloric acidsalt with hot water and precipitating with sodium carbonate, the freebase is obtained. White needles of the melting point 188 C. Calculatedon the sodium salt of the 4-nitro-naphthalene-1-sulfamic acidemployedthe yield is 75%.

Ewample 5.2-amino-5-naphthoylamino-1- methomybenzene 270 'kg's. ofl-methoxy-5-nitrobenzene-2- sulfamic'acid (sodium salt), (produced bysulfon'ating in the amino group of l-methoxy- 2-amino-57nitrobenzene),are reduced as described in (Example 1) and aroylated in aqueoussodasolution by means of 200 kgs. of d-naphthoylechloride thesulfonicgroup is split oif with hydrochloric acid. By re-dissolving thevhydrochloric acid salt with hot water and precipitating with sodiumcarbonate, the free base is obtained. White prisms. melting point 191192Calculated on the sodimn salt of v1-methoxy-5-nitrobenzene-2- sulfamicacid used the yield is 55%.

' 'We claim:

1. The process which comprises sulfonatamino group of 4-nitrol -naph-.

ing in the amino group an aromatic nitroamlne of the general formula:

wherein It stands for a benzene or naphthalene nucleus which may besubstituted by alkyl, alkoXy or halogen, reducing the nitro group inaqueous solution, aroylating the amino group by means of a benzoylornaphthoyl-halide which may be substituted by alkyl, alkoxy, halogen, orthe nitro group and splitting up the sulfamic group by heating with adilute mineral acid. a

2. The process which comprises sulfonating in the amino group anaromatic nitroamine of the general formula:

wherein R stands for a benzene or naphthalene nucleus which may besubstituted by alkyl, alkoxy or halogen, reducing the nitro group inaqueous solution, aroylating the amino group by means ofb-enzoylchloride which may be substituted by alkyl, alkoxy, halogen orthe nitro group and splitting up the sulfamic group by heating with adilute mineral acid.

3. The process which comprises sulfonating in the amino group acompoundof the general formula:

wherein one y stands for a nitro group and the other y and the ws standfor hydrogen, alkyl, alkoxy or halogen, reducing the nitro group,benzoylating the amino group by means of benzoylchloride, and splittingup the sulfamic group by heating with a dilute mineral acid.

4. The process which comprises sulfonating in the amino group a compoundof the general formula:

wherein one :1 stands for a nitro group and the other 2 and the ws standfor hydrogen or for substituents of the group consisting of methyl,ethyl, methoxy and ethoxy, reducing the nitro group, benzoylating theamino group by means of benzoylchloride, and splitting up the sulfamicgroup by heating with a dilute mineral acid.

5. The process which comprises sulfonating in the amino group a compoundof the general formula:

natures.

l/VILHELM NEELMEIER. WILHELM LAMBERZ.

